Latch mechanism



' June 12, 1945.

c. E. BAZLEY LATCH MECHANISM Filed Sept/ll, 1-942 Will 0.2 4%. b a & m A w U1 Patented June 12, 1 945 LATCH MECHANISM Carl E. Bazley, Schenectady, N. Y., assignor to General Electric New York 1 Company, a corporation. of

Application Se tember 11, 1942, Serial No. 457,900

(c1. 1ss--s7) 10 Claims.

My invention relates to latch mechanism and has for its object a simple and reliable latch mechanism which operates in response to shocks to secure a movable member against'movement 9's aresult of. such shocks. I

'More particularly, my invention relates to shock responsive latchmechanism for latching a reciprocable switch member in 'the position,

either the open circuit or closed circuit, in which i it happens to be when the shock occurs. Thus, if the switch member is in its closed circuit position, it is held in that position, andif the switch member is in its open circuit position, it is secured against movement to its closed position.

I In carrying out my invention in-one form, 1

provide a latch member in the form' of a" ring which surrounds the member to be secured'and which is displaced laterally by a shock with re spect to the member to be secured thereby to engage a latching projecting on the member.

This ring is normally in a central position concentric with the member to be secured so that the member is free to move through the ring.

The'ring is biased to that position by means of a beveled bearing surface on the periphery of the ring which cooperates with a. similar beveled bearing surface on the support for the ring. Preferably, a light spring is provided to center the ring on this bearing surface. For a more complete understanding of my invention, reference should be had to the accompanying drawing, Fig. 1 of which is a view in section of 'latch mechanism embodying, my invention; Fig. 2, is a View similar to Fig. 1 but showing the mechanism in one latching position;

Fig. 3 is a view similar to Fig. 1 but showing the reciprocable part in its raised position; i 4 is a view similar to Fig. 3 but showing the reciprocable part latch in its raised position; Fig. 5 is a diagrammatic view showing the applica tion of my invention to an electric relay; while Figs. 6 and 7 are fragmentary views showing details of construction.

Referring to Fig. 1 of the drawing, in one form of my invention I provide a reciprocable rod I0 which'is arranged to be secured to the movable part or member to be latched, such as theloperat ing plunger II (Fig. 5) of an electric relay, This member In extends slidably into a bore 12 in a normally stationarysupporting member I3 which is arranged to be secured to the supporting body member which is mountedon the member l3 and surrounds the rod l0. The central aperture 16 in the ring is somewhat larger than the rod and when the 'ring' is in its'normal position concentric with the rod shown in Fig. 1, the rod is free to move normally upward or downwardthrough the ring between its closed circuit and open circuit positions provided, of course, that such-movement is not accompanied by shocks sufficient to displace the ring from its normal position shown. Thus the walls of the bore [2 form a mechanical connection between the members Ill and 13 whereby themember ill .is guided by the [walls and caused to move longitudinallyin a constrained path relative tothe member fl 3. For thepur'pose of centering the ring'in this normal position shownin Fig. 1, its periphery is"providedfwith a beveled edge I'l forming a beveled or truncated cone-shaped seat having its smaller endflowermost. This, seat on thering bears on a concentric matching cone-shaped seat l8io'n' the member [3. The seat-.18, as shown, is provided by beveling or reaming out the upper 'end of the bore 12, a cap [9 being provided on the .member l3 above thebearing seat 18 and containing a'bore' 20 which is in eifect a continuation of the bore l2. As shown, the beveled angles of these two seats are complementary so that'when the ring is in a horizontal position, as

shown in Fig. 1 it fitson the seat I8, Preferably,

as shown, the angle of the seats is about 45 degrees with the longitudinal center line of the rod 10 and bore l2. p v

Preferably,'the ring is held against the seat 18 by'a fragile helical spring 2I which surrounds the rod I0 and bears at its lower end on the ring, thespring lying in "an enlarged portion of the. bore 12' in the cap 19. The strength of this spring v will be determined by the violence of the shock required to displace the ring laterally to a latching position. A circular groove (not shown) may be provided in the top of this ring to form a seat for the lower end of the spring and hold the spring in concentric relation with the ring.

In the operation of the device, I have found that a'shock applied to the normally stationary member 13 in any direction, whether lateral or vertical, or a component of such shocks, produces a lateral displacement of the ring so that one side of the ring moves into one or the other of the latching grooves 22 and 23 in the rod l0, depending'upon the position of the rod. When this lateral displacement of the ring occurs, a

vrelay open circuit position, when the shock occ'u'rs the' ring efiectively prevents upwardmoveeral displacement of the ring is in reality produced by movement of the rod. and member i3 by the shock independently of. the ring which. tends to remain stationary by reason of its inertia. This action seems clear when. the shock is applied in a horizontal direction to the member f3 thereby giving the apparent horizontal displace-- ment of the ring. Apparently, however, shocks in a. vertical direction have a substantialbomponent in a horizontal direction for I have found that the latching ring is just as effective inits latching action for vertical as for horizontal shocks. To a certain. extent, the relatively light ring has a bouncing action. on the relatively heavy supporting member l3 which tends to displace the ring laterally.

In the latching action shown in Fig. 2 the shock has been in such a direction as to move the ring laterally towardthe right hand as well as to move the rod l upward. Therod, of course,

was before the shock in its lowermost position and therefore was. free. to move only in an upward direction. It will be observed that thelerthand side of the ring has moved into the upper groove 22 and the lower wall of the groove has engaged the lower side of the ring and has raised the ring against the cap [9. The rod is thus latched effectively against upward movement.

It has, it is true, moved. upward somewhat" to the extent necessary to take up the lost motion between the parts but it is contemplated that this upward movement is not. sufficient to move the bridging contacts 24 and 25 (Fig. to their closed circuit positions into engagement with the stationary contacts. a

It will be understood that the latching condition illustrated in Fig. 2 exists. momentarily, only, in view of the fact that the rod is of course biased by gravity to its lowermost position, shown in Fig. 1. Immediately after the shock, or series of shocksthe rod l0 drops and the ring is moved both by gravity and by the centering spring 2| back to its normal position ofJFlg. 1.

When the rod Ill is in its raised position, as

shown in Fig. 3, the lower groove 23is inside the ring and the upper wall of the, groove is preferably, as shown, somewhat below the upper surface of the ring. thereby to limit the downward movementof the rod to the least amount possible. Upon the occurrence of a shock, the ring '3 apparently displaced laterally to the right, as seen in Fig. 4. This would be caused by a shock applied to the member 13 toward the left. To effect this lateral displacement, the ring. must also tilt itself somewhat, as shown in Fig... 4,

Preferably, as shown in Figs. 6 and '7, the rod I0 is made with a polygonal cross-section, as shown a hexagonal cross-section, at least adjacent the grooves, ior I have found that a hexagonal wall provides a more effective latching engagement with the ring. This is particularly true in latching the rod in its raised position, as shown in Fig. 4. Thus, asshown in Figs. 6 and 7,, the ringmoves under two corners 21 and 28 on the! upper wall of the groove 23 thereby effectively latching the rod. If the rod were circular at, this point, it would be possible for the ring to move under only one point of the wall instead of the. two points 21 and 28.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited. thereto since many modifications may bemade, and I there-' fore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the: United States, is:

l. A shock responsive latch mechanism comprising two members arranged to be connected respectively to supported and supporting bodies, a' first of said members being movable with respect to the second of said members, a latching projection on said first member, and an inertia member substantially and loosely surrounding said first member providing for normal movement of said first member but moved relatively by a shock into an engaging position with said projection so as to prevent movement of said. first member.

2. A shock responsive latch mechanism comprising two members arranged. to be connected respectively to supported and supporting bodies, a first of said members" being slidably movable with respect to the second of said members, a latching projection on said first member, a ring surrounding said first member, and means nor.- mally holding said ring in a position laterally to provide for normal movement of. said first member, said ring being moved relatively by a shock into an engaging position with said projection so as. to prevent slidabl'e movement of said. first memb'erwith' respect to said second member.

3. A shock responsive latch mechanism for. a movable part comprising a rod arranged to be attached to the movable part,v a peripheral latching projection on said rod having. a polygonal cross-section, a member arranged for attachment to the support for the movable part, means slid'ably mounting said rod on said. member, and a ring surrounding said rod having, an aperture larger than said rod to provide for normal freedom of movement of said rod independently of said ring, said ring being, displaceable laterally with respect to. said rod and said. member in response to a shock whereby said latching projection engages said ring. and is secured by said. ring against movement.

4'. A. shock responsive latch mechanism comprising a rod, a member provided. with a. bore forming a guide for said rod whereby said. rodis slidably mounted on said member, a peripheral latching projection on said rod. having a. polygonal cross-section, a latch member surrounding said rod having an aperture larger than said rod to provide for normal freedom. of movement of said rod independently of said latch member, means normally holding. said latch member in. a position laterally to provide for normal movement of said rod, said latch member being dl'splaceable laterally into the path of movement of said projection in response to a shock thereby to secure said rod against longitudinal movement.

5. A shock responsive latch mechanism for a movable part comprising a rodarranged to be attached to the movable part, said rod being provided with a groove, 9, member arranged for attachment to the support for the movable part, said member being provided with an aperture through which said rod extends and the wall of said aperture being beveled to form a seat, a ring surrounding said rod having an aperture larger than said rod to provide for normal freedom of movement of said rod independently of said ring, a seat on said ring engaging said first seat, said groove being inside of said ring when said rod is in one position whereby a shock applied to said member displaces said ring with respect to said member to bring a side of said ring into said groove thereby to latch said rod in'said predetermined position against its bias. 6. A shock responsive latch mechanism for a movable part comprising a rod arranged to be attached to the movable part, said rod being prcvided with a peripheral groove, a member arranged for attachment to the support for the movable part, said member being provided with an aperture through which said rod extends and the wall of said aperture being beveled around said groove to form a cone-shaped seat surrounding saidgroove, a ring surrounding said rod having an aperture larger than said rod to provide for normal freedom of movement of said rod through said ring, a beveled edge on the periphery of said ring forming a cone-shaped seat fitting on said first seat, and a helical spring surrounding said rod bearing on said ring thereby to bias said ring on said first seat to a position concentric with said rod, said groove being inside of said ring when said rod is in a predetermined position whereby a lateral shock applied to said rod and member displaces said ring with respect to said rod and member to bring one side of said ring into said groove thereby to latch said rod in said predetermined position.

7.'A shock responsive latch'mechanism for a movable part comprising a rod arranged to be attached to the movable part so as to be movable lengthwise therewith in a substantially vertical direction, a member arranged .to be attached to a support for the movable part, said member being provided with a bore forming a guide for said rod whereby said rod is slidably mounted on said member, two peripheral grooves on said rod forming between them a peripheral latching projection, said latching projection having a hexagonal cross-section, ,a ring surrounding said rod having an aperture larger than said rod to provide for normal freedom of movement p of said rod independently of said ring, said ring being provided with a beveled edge on its peplied to said member whereby said ring is engaged by the top or bottom of said latching projection in dependence upon whether said rod is in a raised or a lowered position thereby to prevent movement of said rod to the other of said positions. p

' 8. A shock responsive latch mechanism for a movable part comprising a rod arranged to be attached to the movable part so as to be movable lengthwise therewith in a substantially vertical direction, a member arranged to be attached to a support for the movable part, said member being provided with a bore forming a j guide for said rod whereby said rod is slidably mounted on said member, two peripheral grooves on said rod forming between them a peripheral latching projection, said latch projection having a polygonal cross-section, a ring surrounding said rod having an aperture larger than said rod to provide for normal freedom of movement of said rod independently of said ring, said bore being provided with an enlarged portion forming a space for said ring and with top and bottom seats for said ring, means for holding said ring in a central position to provide for-freedom of movement of said rod in said bore, said ring being displaceable laterally with respect to said rod and member in response to a shock applied jection means on said second member, a latch riphery forming normally a supporting seat for said ring and said bore being provided with an enlarged portion forming a space for said ring having a cone-shaped seat normally engaged by the beveled edge of said ring thereby to hold said ring in a central position and provide for freedom of movement of said rod in said bore, a spring surrounding said rod for holding normally said ring in a central position on said seat, said ring being displaceable laterally with respect to member substantially and loosely surrounding said second 'member mounted on said supporting member for displacement laterally in response to a shock applied to said supporting member into engagement with said latching projection ,means thereby to secure said secondmember. against movement by the shock, and means for positioning said latch member in spaced relation with said second member to provide for normal movement of said second member independently of said latch member.

10. The combination with a supporting member of a second member mounted for movement with respect to said supporting member had: and forth in a substantially vertical plane between two positions, latching projection means on said second member, a substantially ringshaped latch member loosely surrounding said ment by the shock, and a substantially cone-" Y shaped seat on said supporting member for said latch member for positioning said latch member normally in spaced relation with said second member to provide for normal movement of said second member independently of said latch member.

CARL E. BAZLEY. 

